It is well known that very small amounts of fluid, when unrestrained, will form into droplets. Rain drops are a familiar example of this development, as are drops from a leaky faucet. It is also well known that the creation of drops is the result of a physical phenomenon known as surface tension.
By definition, surface tension is a property possessed by liquid surfaces whereby they appear to be covered by a thin elastic membrane in a state of tension. From a physical perspective, the phenomenon of surface tension is due to unbalanced molecular cohesive forces in the liquid near its surface. A consequence here is that only small volumes of liquid will form as drops. Nevertheless, because the cohesive forces are unbalanced, they can be easily disrupted. When this happens, the liquid from the drop is dispersed. For example, contact forces against the surface of a drop will cause the drop to quickly disperse.
Several situations can be envisioned wherein it is advantageous to apply only a small volume of a liquid onto a surface area. Of interest here are post-surgical, medical situations that leave internal tissues exposed, such as the well-known laser surgical procedure, photorefractive keratectomy (PRK). In particular, a consequence of PRK is that tissue of the corneal stroma is post-surgically exposed. The exposed area of tissue due to de-epithelialization of the cornea is necessarily rather small, e.g. less than about 9 mm diameter, but it requires immediate attention. Specifically, an application of the liquid medicament mitomycin C is needed to prevent haze. Heretofore, sponges have been widely employed for this purpose. The results, however, have been irregular and variable. This is typically due to sponge contact with the eye, and other ancillary issues that include spillage, trauma to the exposed tissue, infections due to contact, and uneven or incomplete coverage of the surgical area.
In light of the above, it is an object of the present invention to provide a fluid (liquid) medicament applicator that is capable of applying a liquid medicament uniformly over a corneal surface area having predetermined dimensions. Another object of the present invention is to provide a disposable applicator that is capable of accurately and precisely applying a liquid medicament onto a surface area without contacting the surface area with the applicator. Still another object of the present invention is to provide a liquid medicament applicator that is easy to use, is simple to manufacture, and is comparatively cost effective.